Hi-End class video recorders.
Hi-End class video recorders
INTRODUCTION
Earlier in the articles we described the classification of recorders, dividing them into 4 classes:
1. Budget, so-called Econom-class.
2. Average, Medium*class, or, using computer terminology, SOHO (for small offices and home use).
3. Professional, Professional — class.
4. Hi-End class.
A table of dividing DVRs into classes was also given («Algorithm of Security» No. 1*3, 2010) by technical characteristics and areas of application. Adhering to this data, we will begin the story about the top equipment for recording video streams.
WHAT'S INSIDE
The cost of Hi-End video recorders starts from 20 thousand rubles for a 4-channel model. 8* and 16*channel Hi-End DVRs cost from 35*50 thousand rubles. The cost is considerable, and not every project justifies using this equipment. But in some cases, without such equipment, the project will be raw and will not be able to meet the task set by the customer. More precisely, it will not solve this task.
Compression format and recording quality H.264 is the main compression format of Hi*End class recorders. Some models have the ability to configure the key frame of the compression format (the key frame contains all the information about the image in the frame; the intermediate frame can refer to image blocks in the previous key or previous intermediate frames). When the key frame value (the ratio of key and intermediate frames) decreases, the archive depth decreases, this allows you to control the quality of the recorded material and improve the image with a freeze frame or with accelerated playback of the recorded material. The resolution in PAL is 4CIF (D1) — 704 * 576 — this resolution is supported by all Hi*End DVRs, as well as 2CIF (704 * 288) and CIF (352 * 288).
The main advantage of Hi-End recording devices is the recording speed. And it is 25 fps per channel in 4CIF (D1) format — 704 * 576. That is, real-time video at maximum resolution. Various settings are possible, including reducing the recording speed and frame resolution, but this will not be due to the limitation of the recorder itself, but rather to the desire to increase the depth of the archives at the expense of less significant cameras.
On average, at a speed of 400 fps per system and a resolution of 4CIF (D1) — 704 * 576, on a 16-channel DVR with a 1000 GB hard drive, the archive depth will be about 1.5 days in continuous recording mode. Recording in real-time mode at maximum resolution is:
? Absolute control over the situation, there are no gaps in the recording and, as a result, everything that the camera observes is recorded.
? High-quality improvement in the recording of moving objects, especially when there are many of them in one frame.
? Better accelerated viewing and viewing of small image details. Recording modes Hi-End video recorders can record in the following modes:
1. Continuous recording, when recording occurs around the clock.
2. Scheduled recording, when recording is activated at a set time.
3. By detecting motion in the video frame.
4. By sound (the appearance of noise at the object).
5. By signal from external sensors of any type.
6. Combined recording by speed. (Example: constant recording 2 fps, and when movement appears in the frame, recording 25 fps. When the movement disappears, switching to constant recording 2 fps).
7. Combined recording by schedule (at certain hours, recording is performed by movement, and at other times constantly. It is worth noting that professional DVRs can do this too).
The motion recognition system in the frame is well implemented and does not work in case of rain or snow. In some models, you can program the direction of movement. In this case, recording starts only when the movement in the frame occurs in a certain direction. The functions «pre» and «post» recording are similar to the professional series DVR.
«Recording by schedule», by sound, from external sensors we have already considered in previous articles, so we will not dwell on them. All these functions are similar to the capabilities of DVR of other classes, only there are more settings and better implementation.
DVR reaction to an event
Like Prof DVR, Hi-End devices have many possible reactions to an event. Many of the capabilities are comparable with the professional series:
1. Sending messages about an event to a pre-registered e-mail address.
2. Turning on the buzzer built into the DVR.
3. Performing actions on the output relay, which are programmed as NO or NC. In 16-channel DVRs, there are up to 4 programmable output relays.
4. Displaying the image of the channel in which the event occurs on the alarm monitor (SPOT output). In the devices in question, there may be up to 4 SPOT outputs, programmable at the discretion of the client.
5. Control of a PTZ dome camera.
Note that each channel can be linked to one or more executive outputs, as well as the output can be used in conjunction with several
video channels.
Additional functions
The highest class of video recorders has the same functionality as professional ones. The main difference is more flexible settings and extended functionality:
? The ability to work with equipment via RS*232* protocol (POS terminals, cash registers, banking equipment, retail equipment) with input of information directly into the video frame. Some Hi-End devices have up to 8 such inputs.
? Usually the number of audio inputs corresponds to the number of video inputs.
? Direct printing of still images to a printer without using a computer (the same principle as connecting a camera to a printer).
? Using «watermarks» when recording to identify the absence of counterfeiting.
? The presence of not only hidden cameras (viewing certain cameras can be restricted by access rights), but also closed zones in the image (Privacy zone mask).
? Working with «model» frames. Allows you to find not only movement in the frame, but also its static changes, say, an abandoned object or an open door.
Network capabilities are generally similar to the professional class with one exception — the ability to broadcast to the network, practically, live video (configurable parameter) and, in this regard, the use of a gigabit network adapter. Let us recall the description of the network part:
1. The built-in web server allows you to connect to the recorder without installing special software via Internet Explorer + work with the DVR via PDA and 3G* devices.
2. Built-in mail client.
3. Operation of several DVRs in a single system + network load adjustment.
4. Synchronization with world time via the Internet, automatic transition to summer/winter time.
5. Work with DDNS (DynDNS) services, which allow remote access to the recorder without the allocation of a static IP address by the provider.
6. Ability to work with NAS drives not only in local networks, but also via the Internet.
7. Possibility of independently raising the connection with the Internet provider (modem management).
8. Possibility of organizing two-way duplex audio communication between the recorder and a computer on the network.
Viewing and archiving
Viewing is optimal both over the network and on a connected large monitor. Over the network, you can organize joint work of several DVRs with flexible access control. Monitors can be used with a resolution of up to 1920×1080 via HDMI or DVI. Using programmable SPOT outputs (up to 4*x) will allow you to connect up to 5 monitors with individual video on each to the recorder. Some models allow you to customize the viewing window interface and the distribution of cameras on it at your discretion.
Many models of high-end DVRs can install up to 6-8 hard drives (there are models with «hot swap») and create a RAID array up to level 5.
Archiving can be done via USB to external media (flash, HDD), to built-in DVD*RW drives and over the network using specialized software. Some models use external drive connections via e-sata or IEE1394 connectors. Archiving to NAS drives is supported.
WHERE AND WHY WE USE HI
There are not many areas where the use of high-end video recorders is required. Of course, if you have the funds, you can use expensive and high-tech equipment in any project, but there are areas where the use of such equipment is necessary.
Places of mass gathering of people. 6 fps is sometimes not enough to ensure security at airports, stadiums, train stations, where the situation changes every moment and it is necessary to work with many objects in the frame. For further recognition of people's actions and situational moments, maximum resolution and real-time recording are required.
Large supermarkets with recording of information from retail equipment. The larger and more respectable the supermarket, the more functional security equipment it should have.
Banks, financial institutions. Highest recording quality, redundant archiving system (RAID*array), possibility of integration into complex multi-level security systems.
“Safe city” systems, traffic flow control. Integration into complex security systems, where data exchange is carried out over the network and there are additional capabilities, such as recognition of vehicle numbers, railway cars, face recognition.
Strategically important industries that require high-quality recording, such as gold and diamond mining and processing. An alternative to professional-grade DVR. When the customer needs higher-quality recording and advanced network functions.
EQUIPMENT CONFIGURATION
Projects using Hi*End DVR imply the use of good high-resolution cameras with such functions as WDR, DNR, etc. Modern color cameras allow you to get high-quality color images at any time of the day with a resolution of 600 TVL. Hi-End recorders are best combined with them. Again, to get the highest quality result, you should pay attention to the signal transmission lines and camera power supply.
All other recommendations for completing equipment using Hi-nd DVRs correspond to the professional class.
SUMMARY
Let's draw final conclusions:
1. The use of Hi End recorders is justified in cases where:
? High quality recording and real video 25 fps are required;
? Identification of people and their actions is required;
? Remote access to the recorder via the network with advanced capabilities is required;
? It is necessary to integrate several DVRs into the system;
? Registration of license plates of fast-moving vehicles is required;
? Control of external cameras using control automation is required;
? Control of external devices in response to an event is required;
? it is necessary to control various POS/ATM equipment;
? redundancy of archive safety is required;
? protection of recordings with “watermarks” is required;
? work with “exemplary” personnel is necessary.
2. Recommended for use in the following areas:
? the financial sector associated with the constant turnover of cash;
? strategically important industries;
? in large supermarkets with high traffic;
? places of mass gatherings of people;
? “safe city” systems;
? in the widest range of tasks.
We remind you that in order to correctly select equipment for solving a specific problem and the optimal “price/result” ratio, it is better to contact specialists. Ideally, before drawing up the specification, an inspection of the object is necessary to identify all the nuances.
S. Pigorev, Director of Poliset-SB, A. Padom, Director of ALADOKS
Published in the journal «Security Algorithm», No. 5, 2010